ARALDITE® 2018 A/B

• Good UV stability
• Ideal for bonding thermoplastics
• Low shrinkage
• Flexible
• Room temperature curing

Pretreatment

The strength and durability of a bonded joint are dependant on proper pretreatment of the surfaces to be bonded. At the very least, joint surfaces should be cleaned with a good degreasing agent such as acetone, iso-propanol (for plastics) or other proprietary degreasing agents in order to remove all traces of oil, grease and dirt. Low grade alcohol, gasoline, or paint thinners should never be used. The strongest and most durable joints are obtained by either mechanically abrading or chemically etching ("pickling") the degreased surfaces. Abrading should be followed by a second degreasing treatment.

Araldite 2018 structural adhesive is available in cartridges incorporating mixers and can be applied as ready to use adhesive with the aid of the tool recommended by Huntsman Advanced Materials.

Application of adhesive

The resin/hardener mix may be applied manually or robotically to the pretreated and dry joint surfaces. Huntsman's technical support group can assist the user in the selection of a suitable application method as well as suggest a variety of reputable companies that manufacture and service adhesive dispensing equipment. A layer of adhesive 0.002 to 0.004 in (0.05 to 0.10 mm) thick will normally impart the greatest lap shear strength to the joint. Huntsman stresses that proper adhesive joint design is also critical for a durable bond. The joint components should be assembled and secured in a fixed position as soon as the adhesive has been applied.

Equipment maintenance

All tools should be cleaned with hot water and soap before adhesives residues have had time to cure. The removal of cured residues is a difficult and time-consuming operation. If solvents such as acetone are used for cleaning, operatives should take the appropriate precautions and, in addition, avoid skin and eye contact.

Time to minimum shear strength

Typical Cured Properties

Unless otherwise stated, the figures given below were all determined by testing standard specimens made by lap- jointing 4.5 x 1 x 0.063 in (114 x 25 x 1.6 mm) strips of aluminum alloy. The joint area was 0.5 x 1 in (12.5 x 25 mm) in each case. The figures were determined with typical production batches using standard testing methods. They are provided solely as technical information and do not constitute a product specification.

Average lap shear strengths of typical metal-to-metal joints (ISO 4587)

Cured for 16 hours at 40℃ and tested at 23℃ Pretreatment - Sand blasting

Average lap shear strengths of typical plastic-to-plastic joints (ISO 4587)

Cured for 16 hours at 104°F and tested at 73°F. Pretreatment - Lightly abrade and alcohol degrease.

Lap shear strength versus temperature (ISO 4587) (typical average values)
Cure: (a) = 7 days / 73°F; (b) = 24 hours / 73°F and 30 minutes / 176°F

Roller peel test (ISO 4578)
Cured 16 hours / 40°C 23 pli (4.0 N/mm)

Flexural Properties (ISO 178) Cure 16 hours/ 40°C tested at 23°C
Flexural Strength 215 psi (1.48 MPa)
Flexural Modulus 2321 psi (16 MPa)

Elongation at break 45%

Lap shear strength versus immersion in various media (typical average values)
Unless otherwise stated, L.S.S. was determined after immersion for 90 days at 73°F (23°C)

Lap shear strength versus tropical weathering
(40/92, DIN 50015; typical average values) Cure: 16 hours / 104°F (40C); Tested at 73°F (23°C)

Lap shear strength versus heat ageing
Cure: 16 hours / 104°F (40℃)

Thermal cycling
100 cycles of 6 hour duration from -22°F to 158°F (-30°C to 70°C): 1276 psi (8.8 MPa)

To protect against any potential health risks presented by our products, the use of proper personal protective equipment (PPE) is recommended. Eye and skin protection is normally advised. Respiratory protection may be needed if mechanical ventilation is not available or is insufficient to remove vapors. For detailed PPE recommendations and exposure control options consult the product MSDS or a Huntsman EHS representative.

ARALDITE® 2018 A/Bs may be stored for up to one year at room temperature provided the components are stored in sealed containers. The expiry date is indicated on the label. Cartridges should not be stored for long periods after removal from the foil overpack.